openreplay/backend/pkg/messages/primitives.go
2021-05-03 17:53:25 +02:00

155 lines
No EOL
2.7 KiB
Go

package messages
import (
"errors"
"io"
"encoding/json"
"log"
)
func ReadByte(reader io.Reader) (byte, error) {
p := make([]byte, 1)
_, err := io.ReadFull(reader, p)
if err != nil {
return 0, err
}
return p[0], nil
}
// func SkipBytes(reader io.ReadSeeker) error {
// n, err := ReadUint(reader)
// if err != nil {
// return err
// }
// _, err = reader.Seek(n, io.SeekCurrent);
// return err
// }
func ReadData(reader io.Reader) ([]byte, error) {
n, err := ReadUint(reader)
if err != nil {
return nil, err
}
p := make([]byte, n)
_, err = io.ReadFull(reader, p)
if err != nil {
return nil, err
}
return p, nil
}
func ReadUint(reader io.Reader) (uint64, error) {
var x uint64
var s uint
i := 0
for {
b, err := ReadByte(reader)
if err != nil {
return x, err
}
if b < 0x80 {
if i > 9 || i == 9 && b > 1 {
return x, errors.New("overflow")
}
return x | uint64(b)<<s, nil
}
x |= uint64(b&0x7f) << s
s += 7
i++
}
}
func ReadInt(reader io.Reader) (int64, error) {
ux, err := ReadUint(reader)
x := int64(ux >> 1)
if err != nil {
return x, err
}
if ux&1 != 0 {
x = ^x
}
return x, err
}
func ReadBoolean(reader io.Reader) (bool, error) {
p := make([]byte, 1)
_, err := io.ReadFull(reader, p)
if err != nil {
return false, err
}
return p[0] == 1, nil
}
func ReadString(reader io.Reader) (string, error) {
l, err := ReadUint(reader)
if err != nil {
return "", err
}
if l > 10e6 {
return "", errors.New("Too long string")
}
buf := make([]byte, l)
_, err = io.ReadFull(reader, buf)
if err != nil {
return "", err
}
return string(buf), nil
}
func ReadJson(reader io.Reader) (interface{}, error) {
jsonData, err := ReadData(reader)
if err != nil {
return nil, err
}
var v interface{}
if err = json.Unmarshal(jsonData, &v); err != nil {
return nil, err
}
return v, nil
}
func WriteUint(v uint64, buf []byte, p int) int {
for v >= 0x80 {
buf[p] = byte(v) | 0x80
v >>= 7
p++
}
buf[p] = byte(v)
return p + 1
}
func WriteInt(v int64, buf []byte, p int) int {
uv := uint64(v) << 1
if v < 0 {
uv = ^uv
}
return WriteUint(uv, buf, p)
}
func WriteBoolean(v bool, buf []byte, p int) int {
if v {
buf[p] = 1
} else {
buf[p] = 0
}
return p + 1
}
func WriteString(str string, buf []byte, p int) int {
p = WriteUint(uint64(len(str)), buf, p)
return p + copy(buf[p:], str)
}
func WriteData(data []byte, buf []byte, p int) int {
p = WriteUint(uint64(len(data)), buf, p)
return p + copy(buf[p:], data)
}
func WriteJson(v interface{}, buf []byte, p int) int {
data, err := json.Marshal(v)
if err != nil {
log.Printf("JSON encoding error: %v", err)
return WriteString("null", buf, p)
}
return WriteData(data, buf, p)
}